The AMX-30 is a main battle tank designed by GIAT, first delivered to the French Army in 1966. The first five tanks were issued to the 501st Régiment de Chars de Combat (Tank Regiment) in August of that year. The production version of the AMX-30 weighed 36 metric tons (40 short tons), and sacrificed protection for increased mobility. The French believed that it would have required too much armour to protect against the latest anti-tank threats, thereby reducing the tank's maneuverability. Protection, instead, was provided by the speed and the compact dimensions of the vehicle, including a height of 2.28 metres. It had a 105-millimetre (4.1 in) cannon, firing an advanced high explosive anti-tank warhead known as the Obus G. The Obus G used an outer shell, separated from the main charge by ball bearings, to allow the round to be spin stabilized by the gun without affecting the warhead inside. Mobility was provided by the 720 horsepower (540 kW) HS-110 diesel engine, although the troublesome transmission adversely affected the tank's performance.